Monday, August 28, 2006

Cardiac Radiology For Medical students


Just an experiment, was wondering if it would be much easier for medical students to remember facts if we used illustrations to aid memory...

Gadolinium related to Nephrogenic Systemic Fibrosis?

Nephrogenic Systemic Fibrosis: Suspected Causative Role of Gadodiamide Used for Contrast-Enhanced Magnetic Resonance Imaging by Peter Marckmann et al in J Am Soc Nephrol 17: 2359-2362, 2006
"INTRODUCTION-Nephrogenic systemic fibrosis is a new, rare disease of unknown cause that affects patients with renal failure. Since 1997, a total of approximately 200 cases of nephrogenic systemic fibrosis (NSF), previously known as nephrogenic fibrosing dermopathy, have been reported worldwide. The appearance of this new and serious disease has triggered considerable interest as to possible causative factors, including newly introduced clinical practices. However, until now, the eliciting factor(s) has not been identified.
COURSE- The typical course begins with subacute swelling of distal parts of the extremities and is followed in subsequent weeks by severe skin induration and sometimes anatomic extension to involve thighs, antebrachium, and lower abdomen. The skin induration may be aggressive and associated with constant pain, muscle restlessness, and loss of skin flexibility. In some cases, NSF leads to serious physical disability, including wheelchair requirement. NSF initially was observed in and thought to affect solely the skin (thus the initial term nephrogenic fibrosing dermopathy), but more recent patient reports have demonstrated that several organs may be involved.
POSSIBLE MECHANISMS-Gadodiamide belongs to the group of extracellular contrast media that are used for MRI. It is a non–tissue-specific and nonionic low-osmolar (650 mOsm/kg) agent. Gadodiamide is almost exclusively excreted renally and therefore has a markedly prolonged half-life in patients with renal failure, including dialysis patients. The gadodiamide half-life of healthy volunteers is 1.3 h, of patients with end-stage renal failure is 34.3 h, of hemodialysis patients is 2.6 h, and of peritoneal dialysis patients is 52.7 h. It previously was considered a safe agent, even in patients with renal failure. The molecular structure of chelate-binding (diethylenetriaminepentaacetic acid-bis-methylamide) Gd is linear. Gadodiamide formulation differs from most other non–tissue-specific extracellular MRI agents by having an excess chelate (12 mg/ml). Whether this could have an impact on NSF development is not known. Alternatively, NSF could be a toxic reaction to free Gd that is liberated from gadodiamide. Free Gd is highly toxic, in particular in its ionic form (Gd3+). Gadodiamide leaves two to four times more Gd in the bone than gadoteridol in patients with normal renal function. Because of the longer half-life of contrast Gd-based media in patients with ESRD, authors speculate that Gd liberation might be causing NSF.
CONCLUSION-This study therefore reviewed all of the authors’ confirmed cases of nephrogenic systemic fibrosis with respect to clinical characteristics, gadodiamide exposure, and subsequent clinical course. It was found that all had been exposed to gadodiamide before the development of nephrogenic systemic fibrosis. The delay from exposure to first sign of the disease was 2 to 75 d (median 25 d). Odds ratio for acquiring the disease when gadodiamide exposed was 32. These findings indicate that gadodiamide plays a causative role in nephrogenic systemic fibrosis."

Sunday, August 27, 2006

Radiology Grand Rounds-III

Welcome to the Third Edition of the monthly summary of the best in the Radiology Blogsosphere known as “ Radiology Grand Rounds”. Grand Rounds is an old tradition that doctors have. Once a week, they get together and talk about one case in detail. Keeping up with this tradition this Carnival of Medical Imaging has been named “Radiology Grand Rounds”. Every physician would agree that Subspecializtion is the need of the hour in medical field, hence the concept of a specialized Radiology Grand Rounds. Radiology Grand Rounds will be hosted on last Sunday of each month, the schedule and archive will be available at- Radiology Grand Rounds. I would like to thank all the contributors for this edition of Radiology Grand Rounds.

Theme For this weeks’ Radiology Grand Rounds is a Magazine, all of us medical men are used to the Scientific Radiology Periodicals so I thought "Radiology Grand Rounds" would be more entertaining if featured like a Magazine.



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CASE FILES

Col(Retd) MGK Murthy from Department of Radiology, NIMHNAS Delhi has sent a very interesting MR image.
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"17 yr old boy with severe headache for some weeks duration. A solitary hyperintense structure in frontoparietal region right side probably vein of tolard is noted. This is suggestive of cortical venous thrombosis and it may or may not be bright on diffusion depending on the duration. Superior Sagittal sinus is normal. No haemorrhage is seen. It needs hypercoagulable state work up and anticoagulants. It is expected to clear in about 6 weeks post treatment MRI. Any feedback about this case is welcome here- drmgkmurthy@gmail.com"


Bhavin in his site Spot Diagnosis features a Radiological Sign “The Fallen Fragment Sign
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“One of the complications of a simple bone cyst is fracture. The fracture is often transverse and one sign that is touted is the "fallen fragment sign", due to fragments of bone that are seen in the dependent portion on erect images usually in the inferior aspect of the cyst.”


Scan Man presents describes two cases of ectopic pregnancy with detailed account of their sonographic findings.Medline Plus, the online medical encyclopedia defines an ectopic pregnancy as one that occurs when a fertilized egg implants in tissue outside of the uterus, and the placenta and fetus begin to develop there. The most common site is within a fallopian tube. In a typical ectopic pregnancy, the fertilized ovum (embryo) implants in the lining of the fallopian tube. As it grows, it stretches the fallopian tube and causes pain. If it is not detected early and treated, the growing gestational sac bursts through the fallopian tube causing massive internal bleeding and hypovolemic shock. This makes ruptured ectopic the leading cause of maternal death in the first trimester of pregnancy. Ultrasound Findings- On the abdominal ultrasound, I found what looked like an organized blood clot in the rectovaginal pouch. This was confirmed on transvaginal ultrasound. There was approximately 250 to 300 cc of clotted blood in the rectovaginal pouch. Additionally, the left adnexa showed an irregular ectopic gestational sac of about 6 weeks size with a yolk sac inside.

THOUGHT PROVOKING POSTS

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Sumer’s Radiology Site points to newspaper reports on harmful effects of Ultrasound on mice brain and asks-Is Medical Imaging entirely safe?

This is somehing i read in the newspaper today morning!! I hope Tom Cruise read this too, although ultrasound is a very safe investigation too much of everything can be harmful...This study should discourage recreational ultrasound use...Ultrasound affects brain in foetus
"Ultrasound disrupts the brain development of unborn mice, researchers said in a study published on Monday that adds to growing evidence that too many ultrasound scans could also affect human foetuses. Prolonged ultrasound scans of the brains of fetal mice interfered with a process known as neuronal migration in which neurons move from one place to another, the team at Yale University in Connecticut reported.


Tales from The womb points to an article in Last week's New England Journal had a very fine manuscript demonstrating that MRI is now the best method of predicting neurodevelopmental insult in premature infants. Neonatal MRI to Predict Neurodevelopmental Outcomes in Preterm Infants.
“Fortunately or unfortunately, this has the possibility of replacing cranial ultrasound overnight as the discharge screen of choice for determining the type of developmental follow up premature infants need. Ultrasounds cost hundreds of dollars; MRIs cost triple to quadruple as much. On the one hand, if it allows us to focus diminishing out-patient resources on the ones who need it most - fantastic. On the other, if we are paying out more to screen all these infants (and remember that one in every eight infants is born premature) then just what kind of cost savings do we think we'll get out of this (versus sending a few more patients to out patient followup visits and doing serial developmental exams)?”

Scan Man Points to an extremely useful article by Dr. John R. Wilcox, M.D., titled ‘The Written Radiology Report‘ in the July edition of Applied Radiology Online. The purpose of the article is to help radiologists improve the quality of their written radiology reports by reviewing the components of a report, addressing grammar and writing style, and considering appropriate standardization.
“Part of the problem with radiology reports arises because we do not really understand how important this document has become to the nonradiologist caregiver. This lapse is more understandable when you realize that most major radiology textbooks do not address the subject of report composition. This would be equivalent to a journalism textbook without a chapter on how to write an article. But journalism and radiology have a lot in common. Both professions require spending a great deal of time gathering “facts” and “data” and then reporting that material in written form for a reader.”

Marian Pop sends us a story on a case of suspected Battered baby. Full story in Romanian is here. English translation-

"Ancuta is 1.3 years old.She is scared and stressed, especially because she doesn't know what'sgoing to happen to her.She's in for a shoulder radiography. And she doesn't want to stay there byherself. And if anyone touches her, she starts crying.Actually her name is not Ancuta. I call her that way because today names doesn't matter.When we have to "make a photo" of a small child the mother or the otherparent enters with her, receive an leaded coat and try to hold the childstill for a second, just enough for us to shoot. Otherwise we'll just irradiate the child and mother for no reason.Ancuta doesn't want to stay. Neither stories nor games won't make her staystill. When she's about to lye down she starts crying and try to get up.The mother can't hold her still.One of the nurses gets into the X-ray room. He's in the early 30's andhe's done this times and again. He ain't scared of 3 more gamma rays. Ihope. He enters and helps the mother to hold the child still. And togetherthey hardly make her stay still.Quick- exposure. And in the exact moment we exposed everyone moves, makingour efforts in vain. We caught just a small part of the humerus and thenurse's hand. We must repeat it, there's no other way. And all this whileAncuta cries her heart out, the mother is already on the edge of breaking"what are you doing to my child...?" and everyone is tensed.30 seconds later we see the image- mistery solved: clavicle fracture, witha humerus dislocation. We stay and look at the monitor with an absentmind.For a while before my eyes pass all the Caffey pages regarding the XTrauma syndrome (or how is it's name). Battered child syndrome. I'm scaredand ashamed to look in mother's eyes. I don't know what to say. Did shefell? Did she hit into something? Is it an too energetic child and someonetried an "correction"?I don't have the time to ask. Ancuta has calmed down, the mother take herout on the corridor and leaves towards the referring physician. We sendthe images thought the internal network. The next patient is alreadyundressed and positioned. In 5 minutes everything will become history..I get up and light a cigarette. I know, they're bad for my health, butthey calm me.I'm still moved by what i just saw. Maybe there will be a socialinvestigation, maybe everything was just in my imagination.I throw the cigarette, I'm already late. The patients are waiting.But, still...., how will Ancuta sleep tonight?"


INFORMATION FILES


Jon Mikel of Unbounded Medicine presents a patient handout of NEC ( Necrotizing enterociloitis) with a classic abdominal plain film. Radiographic findings in NEC-Marked abdominal distention, dilated loops, pneumatosis intestinalis (bubbles of gas in bowel’s wall) and/or free intraabdominal air.


UNUSUAL RADIOLOGY

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Mikhail Serebrennik of Filmjacket.com presents an abdominal Radiograph of a 58 y.o. mentally challenged female with abdominal pain.

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The Radiographs and CT images are must see, it shows needles, needles and needles everywhere!!



This one is must watch for all, this post by dogscatskidslife showing an usual finding in a Cat’s Ultrasound.
“A 2 1/2 year old neutered male cat was sent to us for an ultrasound a while back. The doctor who sent it said that the cat had FLUTD (feline lower urinary tract disease). He had been treating this cat for many months and didn't feel like any progress was being made. So he was wanting an ultrasound to see if there could be stones in the bladder that were not showing up on radiographs (x-rays).I did a complete ultrasound on the cat which was normal, until I got to the urinary bladder. I had located a foreign body that was linear in appearance. "What is that?"After a few minutes, I had determined that I had found a urinary catheter inside of the cat's bladder.”


RADIOLOGICAL QUIZ
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Aleksandr Kavokin MD, PhD of RDoctor Medical Portal presents a RADIOLOGY QUIZ. So, click here to-
Test your knowledge of Radiology.


Mikhail Serebrennik of Filmjacket.com presents a 57 y.o. male, no history provided. Can you make a diagnosis?



That wraps up this month's highlights of the Radiology blogosphere. Hope the readers enjoyed the third edition of the Radiology Grand Rounds. If you liked any of these blogs, keep visiting them. Please email me at sumerdoc@yahoo.com if you are interested in hosting future Radiology Grand Rounds. Archive for the Radiology Grand Rounds here-Radiology Grand Rounds.
For More updates on Radiology Grand Rounds A new discussion Group
has been created here, send me a mail to be invited to the group.
Group name: Radiology Grand Rounds
Group home page: http://groups.google.co.in/group/radgrandrounds
Group email address radgrandrounds@googlegroups.comBe sure to tune in Next Month Last Sunday 24th September, when Grand Rounds
will be hosted at- ScanMan’s Notes A site by an Indian Radiologist. Send the Submissions to-
dr.scanman@yahoo.co.in

Monday, August 21, 2006

Submissions Requested-Radiology GrandRounds-III


Dear Friends
As you all know Third edition of the monthly summary of the Radiology Blogosphere is coming up on the last Sunday of this month, 27th AUGUST. So Hurry Up!! rush in your Radiology Related posts to me at-
sumerdoc-AT-yahoo-DOT-com
Please Note you need not be a Radiologist to post, I am looking forward to posts from all technicians, students, Physicians, nurse etc...
Details about future schedule and guidelines-
Radiology Grand Rounds

Friday, August 18, 2006

Significance of Virchow-Robin Spaces on MRI

"Virchow-Robin spaces (VRS) are perivascular spaces in the brain and can be visualized on magnetic resonance images (MRI). Authors evaluated the VRS in 125 healthy subjects (age range 1-30 years) using high-resolution 3D images, and in 36 patients (age range 2-16 years) with normal MRI, using routine clinical sequences. VRS were visible in all high-resolution images of the 125 healthy subjects. Two of them revealed dilated VRS, giving a prevalence of 1.6%. VRS could be visualized in 29 (80%) of the 36 paediatric clinical scans; none was dilated.From the results of this study and the literature on the nature and pathology of VRS, authors conclude that VRS on MR images of healthy individuals are normal findings, even if they are dilated. A judgement on whether dilated VRS in an individual patient is a normal variant or part of a disease process can be made by taking into account the appearance of the adjacent tissue on MRI and the clinical context."

Thursday, August 17, 2006

Recieving Radiotherapy, Be Careful You may trigger Alarms on the Airport!

Radiotherapy patients can trigger airport radiation alarms
Patients who undergo diagnostic and therapeutic procedures involving radioisotopes must be informed that they might trigger radiation alarms during security checks. Gangopadhyay and colleagues (p 293) describe the case of a 46 year old man who received radioiodine treatment for recurrent thyrotoxicosis. The nuclear medicine department did not tell the patient that he might set off radiation detectors. Six weeks later, the patient was detained at Orlando airport in the US after he triggered a radiation alarm. He was released after a long period of investigation and much embarrassment. The half life of the isotope and the increasing sensitivity of the detectors in airports must be considered when such warnings are given, the authors add.
Reference- BMJ 2006;333 (5 August), doi:10.1136/bmj.333.7562.0-a

Tuesday, August 15, 2006

Upcoming conference on Radiology in India

The REF holds radiology review courses twice or thrice a year. The Residents' Review Courses are meant exclusively for residents. All speakers are experts in their respective fields and bring to these CMEs a combination of experience and expertise.
Link Here-
10th Residents' Review Course - 5th October to 8th October 2006

Friday, August 11, 2006

Urine attenuation ratio: A new CT indicator of renal artery stenosis.

Reference- AJR Am J Roentgenol 2006 Aug;187(2):532-40. By Sung CK et al.
"Urine CT attenuation ratio in 22 patients with significant RAS ranged from 1.11 to 4.76 (mean, 2.07). The two patients with moderate RAS showed ratios of 1.83 and 1.23. The others (n = 48) had a urine CT attenuation ratio that ranged from 1.00 to 1.54 (mean, 1.07). The difference of the ratio between the RAS group and the normal group was statistically significant.
At a cutoff value of 1.22, the sensitivity, specificity, positive predictive value, and negative predictive value of the urine CT attenuation ratio in the diagnosis of significant RAS were 95%, 96%, 91%, and 98%, respectively. The urine CT attenuation ratio is a simple and reliable indicator with which to detect and lateralize significant RAS and is a useful adjunct to helical CTA."

Wednesday, August 09, 2006

Is All Routine Medical Imaging actually safe?

This is somehing i read in the newspaper today morning!! I hope Tom Cruise read this too, although ultrasound is a very safe investigation too much of everything can be harmful...This study should discourage recreational ultrasound use...

Ultrasound affects brain in foetus

"Ultrasound disrupts the brain development of unborn mice, researchers said in a study published on Monday that adds to growing evidence that too many ultrasound scans could also affect human foetuses. Prolonged ultrasound scans of the brains of fetal mice interfered with a process known as neuronal migration in which neurons move from one place to another, the team at Yale University in Connecticut reported. "Proper migration of neurons during development is essential for normal development of the cerebral cortex and its function," Pasko Rakic, chair of the Department of Neurobiology at Yale, said in a statement. "We have observed that a small but significant number of neurons in the mouse embryonic brain do not migrate to their proper positions in the cerebral cortex following prolonged and frequent exposure to ultrasound." Writing in the Proceedings of the National Academy of Sciences, Rakic's team said the findings do not necessarily mean that ultrasound of human foetuses is dangerous but they said doctors and pregnant mothers should probably keep the scans to a minimum. But several studies have suggested that ultrasound may affect the developing brain, not necessarily adversely. For instance, a 1993 study published in the Lancet medical journal found that babies given ultrasounds before they were born were more likely to be left-handed. A separate study found a possible decrease in weight in newborns who were scanned, while a third found delayed speech. But another study showed that children who had received ultrasound exams before birth actually did better in language tests when they were older, said Verne Caviness of Massachusetts General Hospital. he said. "Therefore I want to emphasise that our study in mice does not mean that use of ultrasound on human foetuses for appropriate diagnostic and medical purposes should be abandoned. On the contrary: ultrasound has been shown to be very beneficial in the medical context," Rakic added. He said the study suggests that pregnant women should not get multiple ultrasound scans for fun or out of curiosity. "
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Now about Chest X-Ray, this is what the Diagnostic Imaging says about CXR in breast cancer
"An analysis of 1600 women with BRCA1 and BRCA2 mutations suggests that exposure to chest x-rays may increase the risk of breast cancer. Exposure before the age of 20 may be linked to particularly heightened risk. The research, conducted by a consortium of European cancer centers, was the first to analyze the impact of low-level x-ray exposure among women at genetically high risk for the disease. The study was published online June 26 in the Journal of Clinical Oncology. Investigators noted two primary limitations of the study. The first was the potential for recall bias, meaning that women who had developed breast cancer might be more likely to remember receiving an x-ray than women who had not been diagnosed with the disease. The second was lack of data on the specific dose and timing of radiation that was received. "

Sunday, August 06, 2006

DTI in Professional Boxers

Distribution of microstructural damage in the brains of professional boxers: A diffusion MRI study. By Chappell MH et al in J Magn Reson Imaging 2006 Jul 28; [Epub ahead of print]

"Diffusion tensor imaging (DTI) was used to determine the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) in the brains of 81 professional male boxers and 12 male control subjects. Voxel-based analysis (VBA) of both the diffusion and anisotropy values was performed using statistical parametric mapping (SPM). Increases in the ADC, and decreases in FA were identified in deep white matter (WM), while decreases in ADC were identified in cortical gray matter (GM). Regions of positive correlation between ADC and age were also found in both the boxer and control groups, although the regions and strength of the correlation were not the same in each group. Using VBA, authors localized previously unreported abnormalities in the brains of professional boxers. These abnormalities are assumed to reflect cumulative (chronic) brain injury resulting from nonsevere head trauma."

Useful link on CTisus Site about Critical Points in CT

Elliot K. Fishman, of the Website CTisus adds an interesting column on Pearls in CT on his site. He goes like-
"Imaging "pearls" or critical points have been as much a part of radiology as teaching files. Therefore, we are pleased to bring you our new "pearls" section which will bring to our readers key vignettes on imaging. I will do this monthly based on either the current literature or information that comes across my desk. "
Extremely useful or i might say a Pearl of a link for Radiology Residents :-)

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